freebsd-skq/sys/powerpc/include/dbdma.h
Nathan Whitehorn b798355b99 Expand the DBDMA API to allow setting device-dependent control bits. While
here, clean up and document this a little.

Submitted by:	Marco Trillo
MFC after:	1 week
2008-09-27 15:41:16 +00:00

151 lines
5.2 KiB
C

/*-
* Copyright (c) 2008 Nathan Whitehorn
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_DBDMA_H_
#define _MACHINE_DBDMA_H_
#include <sys/param.h>
#include <machine/bus.h>
/*
* Apple's DBDMA (Descriptor-based DMA) interface is a common DMA engine
* used by a variety of custom Apple ASICs. It is described in the CHRP
* specification and in the book Macintosh Technology in the Common
* Hardware Reference Platform, copyright 1995 Apple Computer.
*/
/* DBDMA Command Values */
enum {
DBDMA_OUTPUT_MORE = 0,
DBDMA_OUTPUT_LAST = 1,
DBDMA_INPUT_MORE = 2,
DBDMA_INPUT_LAST = 3,
DBDMA_STORE_QUAD = 4,
DBDMA_LOAD_QUAD = 5,
DBDMA_NOP = 6,
DBDMA_STOP = 7
};
/* These codes are for the interrupt, branch, and wait flags */
enum {
DBDMA_NEVER = 0,
DBDMA_COND_TRUE = 1,
DBDMA_COND_FALSE = 2,
DBDMA_ALWAYS = 3
};
/* Channel status bits */
#define DBDMA_STATUS_RUN (0x01 << 15)
#define DBDMA_STATUS_PAUSE (0x01 << 14)
#define DBDMA_STATUS_FLUSH (0x01 << 13)
#define DBDMA_STATUS_WAKE (0x01 << 12)
#define DBDMA_STATUS_DEAD (0x01 << 11)
#define DBDMA_STATUS_ACTIVE (0x01 << 10)
/* Set by hardware if a branch was taken */
#define DBDMA_STATUS_BRANCH 8
struct dbdma_command;
typedef struct dbdma_command dbdma_command_t;
struct dbdma_channel;
typedef struct dbdma_channel dbdma_channel_t;
int dbdma_allocate_channel(struct resource *dbdma_regs, u_int offset,
bus_dma_tag_t parent_dma, int slots, dbdma_channel_t **chan);
int dbdma_resize_channel(dbdma_channel_t *chan, int newslots);
int dbdma_free_channel(dbdma_channel_t *chan);
void dbdma_run(dbdma_channel_t *chan);
void dbdma_stop(dbdma_channel_t *chan);
void dbdma_reset(dbdma_channel_t *chan);
void dbdma_set_current_cmd(dbdma_channel_t *chan, int slot);
void dbdma_pause(dbdma_channel_t *chan);
void dbdma_wake(dbdma_channel_t *chan);
/*
* DBDMA uses a 16 bit channel control register to describe the current
* state of DMA on the channel. The high-order bits (8-15) contain information
* on the run state and are listed in the DBDMA_STATUS_* constants above. These
* are manipulated with the dbdma_run/stop/reset() routines above.
*
* The low order bits (0-7) are device dependent status bits. These can be set
* and read by both hardware and software. The mask is the set of bits to
* modify; if mask is 0x03 and value is 0, the lowest order 2 bits will be
* zeroed.
*/
uint16_t dbdma_get_chan_status(dbdma_channel_t *chan);
uint8_t dbdma_get_device_status(dbdma_channel_t *chan);
void dbdma_set_device_status(dbdma_channel_t *chan, uint8_t mask,
uint8_t value);
/*
* Each DBDMA command word has the current channel status register and the
* number of residual bytes (requested - actually transferred) written to it
* at time of command completion.
*/
uint16_t dbdma_get_cmd_status(dbdma_channel_t *chan, int slot);
uint16_t dbdma_get_residuals(dbdma_channel_t *chan, int slot);
void dbdma_clear_cmd_status(dbdma_channel_t *chan, int slot);
/*
* The interrupt/branch/wait selector let you specify a set of values
* of the device dependent status bits that will cause intterupt/branch/wait
* conditions to be taken if the flags for these are set to one of the
* DBDMA_COND_* values.
*
* The condition is considered true if (status & mask) == value.
*/
void dbdma_set_interrupt_selector(dbdma_channel_t *chan, uint8_t mask,
uint8_t value);
void dbdma_set_branch_selector(dbdma_channel_t *chan, uint8_t mask,
uint8_t value);
void dbdma_set_wait_selector(dbdma_channel_t *chan, uint8_t mask,
uint8_t value);
void dbdma_insert_command(dbdma_channel_t *chan, int slot, int command,
int stream, bus_addr_t data, size_t count, uint8_t interrupt,
uint8_t branch, uint8_t wait, uint32_t branch_slot);
void dbdma_insert_stop(dbdma_channel_t *chan, int slot);
void dbdma_insert_nop(dbdma_channel_t *chan, int slot);
void dbdma_insert_branch(dbdma_channel_t *chan, int slot, int to_slot);
void dbdma_sync_commands(dbdma_channel_t *chan, bus_dmasync_op_t op);
#endif /* _MACHINE_DBDMA_H_ */